The HAL HJT 39, aka CAT (Combat Air Trainer), was an Advanced Jet Trainer (AJT) project proposal by

Hindustan Aeronautics Limited Hindustan Aeronautics Limited (HAL) is an Indian state-owned aerospace and defence (military), defence company, headquartered in Bangalore, India. Established on 23 December 1940, HAL is one of the oldest and largest aerospace and defence manuf ...

(HAL) for the

Indian Air Force The Indian Air Force (IAF) is the air arm of the Indian Armed Forces. Its complement of personnel and aircraft assets ranks third amongst the air forces of the world. Its primary mission is to secure Indian airspace and to conduct aerial w ...

. HAL HJT 39 CAT Programme was Announced at Aero India, February 2005,Aero India - Local rival to BAE Hawk proposed - Flight Global, 15 FEBRUARY, 2005
/ref> with mockup of front fuselage and cockpit shown. It was projected to fly within three and a half years of go-ahead with airframe and engine commonality with

HAL HJT-36 Sitara The HAL HJT-36 ''Sitara'' ( Sitārā: "''star''") is a subsonic intermediate jet trainer aircraft designed and developed by Aircraft Research and Design Centre (ARDC) and built by Hindustan Aeronautics Limited (HAL) for the Indian Air Force and ...

, avionics comparable with those of HJT-36 and

HAL Tejas The HAL Tejas is an Indian, single engine, delta wing, light multirole fighter designed by the Aeronautical Development Agency (ADA) in collaboration with Aircraft Research and Design Centre (ARDC) of Hindustan Aeronautics Limited (HAL) for t ...

Design

CAT was Planned as a twin engine transonic “Lead in Fighter Trainer” (LIFT) with a very substantial ground attack capability with a maximum speed of 1,000 km/hr. CAT was to feature Multi Function Displays (MFD) for tactical navigation, Radar Warning Receiver (RWR) and indigenous CSIO/BEL-developed

Head Up Display A head-up display, or heads-up display, also known as a HUD (), is any transparent display that presents data without requiring users to look away from their usual viewpoints. The origin of the name stems from a pilot being able to view informa ...

(HUD) and Up Front Control Panel (UFCP), used on the LCA. The HUD would display both navigation and weapon aiming. CAT also features redundancy features like stand by instrumentation system,

Fly-by-Wire Fly-by-wire (FBW) is a system that replaces the conventional manual flight controls of an aircraft with an electronic interface. The movements of flight controls are converted to electronic signals transmitted by wires, and flight control co ...

(FBW), hands-on-throttle-and-stick HOTAS),

INS INS or Ins or ''variant'', may refer to: Places * Ins, Switzerland, a municipality * Creech Air Force Base (IATA airport code INS) * Indonesia, ITF and UNDP code INS Biology *'' Ins'', a New World genus of bee flies * INS, the gene for the insul ...

along with

GPS The Global Positioning System (GPS), originally Navstar GPS, is a Radionavigation-satellite service, satellite-based radionavigation system owned by the United States government and operated by the United States Space Force. It is one of t ...

receiver, flight control computer and display processor. The avionics would be confirming 32-bit dual mil 1553B Bus Standard. The FBW planned consist two digital channels and one engine analog channel.

Full Authority Digital Engine Control A full authority digital engine (or electronics) control (FADEC) is a system consisting of a digital computer, called an "electronic engine controller" (EEC) or "engine control unit" (ECU), and its related accessories that control all aspects of ai ...

(FADEC) will be implemented for better handling. Some other features of the modern

cockpit A cockpit or flight deck is the area, usually near the front of an aircraft or spacecraft, from which a Pilot in command, pilot controls the aircraft. The cockpit of an aircraft contains flight instruments on an instrument panel, and the ...

are automatic pressure cabin and temperature control systems, zero / zero

ejection seat In aircraft, an ejection seat or ejector seat is a system designed to rescue the aircraft pilot, pilot or other aircrew, crew of an aircraft (usually military) in an emergency. In most designs, the seat is propelled out of the aircraft by an ex ...

and crew emergency escape system. Radar is optional, but a new radar is to be developed.

Airframe

Among the prominent External design features revealed were a moderately-swept wing, with no wing-body blending or wing root strakes, a prominent vertical fin. The low wing sweep will give a good low-speed performance and excellent handling characteristics essential for the trainer role. The wing will also have a clean leading edge, while having high-lift devices on the trailing edge, for good runway performance. The HJT-39 will be an all-composite aircraft.

Cockpit

CAT was Planned to have tandem seat configuration which lets the trainee sit in the Front Cockpit with considerable stagger between the front and rear seats. The cockpit is designed in such away that the vision for both the occupants is the maximum. The trainer has a bird’s eye view of the trainee’s action and controls. The cockpit will a state of the art

glass cockpit A glass cockpit is an aircraft cockpit that features electronic (digital) flight instrument displays, typically large LCD screens, rather than the traditional style of analog dials and gauges. While a traditional cockpit relies on numerous mech ...

having Head up Display (HUD), Head down instruments and weapon aiming controls. The

ergonomics Human factors and ergonomics (commonly referred to as human factors) is the application of psychological and physiological principles to the engineering and design of products, processes, and systems. Four primary goals of human factors learnin ...

of the cockpit is another key feature of the CAT.

Engine

In view of the ground attack requirements, it was to be powered by two

NPO Saturn AL-55 The NPO Saturn AL-55 is a high performance turbofan engine manufactured by NPO Saturn Russia, for powering advanced trainers, unmanned aerial vehicles (UAV) and light attack aircraft. A variant of the AL-55I powers the HAL HJT-36 Sitara Indian jet ...

turbofans of 2,200 kg thrust each, compared to the 1,800 kg thrust of the variant for the single-engined HJT-36 intermediate jet trainer

Armament

CAT was to feature 5 hard points. The external stores with practice bombs, rockets, missiles and a gun in central fuselage. The maximum takeoff weight with external stores was projected as 9,500 kg. The HJT-39 will also have a virtual training capability, with radar simulation, computerised training aids and the like. An item of optional equipment for the HJT-39 is an On-Board Oxygen Generation System (OBOGS). HAL plans to deliver a prototype in 39 months after the clearance from the government with the project cost of Rs 750 crore. (2005) The project was most likely shelved with no further news. India bought Hawk 132 AJTs

References

Citations

External Source

*http://www.business-standard.com/india/news/hal-to-unveil-concept-combat-air-trainer/200342/ *https://web.archive.org/web/20110311025722/http://frontierindia.net/revisiting-indian-combat-air-trainer-project {{HAL aircraft HJT 39 Proposed aircraft of India